The research in the current grant period will focus on applications of the intramolecular Diels-Alder reaction to the total synthesis of Marasmic acid lycorine, and pretazzetine. Other areas of interest include applications of vinyl ether chemistry to the total lsynthesis of calcimycin (A-23187), the prostaglandins and curvulavin. Finally, work on a fragmentation approach to Ophiobolin F will be completed. These substances exhibit a wide variety of biological activity, and the general methodology and strategies developed are applicable to the construction of numerous other biologically active materials.